The present application relates generally to a utility disconnect switch (UDS) and more particularly but not exclusively to a fast utility disconnect switch for a single conversion uninterruptable power supply (UPS). The ability of a UPS to transfer between a primary power supply (e.g., a utility grid) and a back-up power supply (e.g., battery, capacitors and related interface converter) without influencing production quality and losses is a challenge for a number of industrial systems and process. Furthermore, the ability to transfer from grid power to a back-up power supply very quickly, e.g., in 1 ms or less, would be desirable in certain applications. Present approaches to UPS transitions between a primary power supply and a backup power supply, such as thyristor-based or silicon controlled rectifier (SCR)-based systems, fail to adequately meet these challenges and suffer from a number of additional drawbacks and shortcomings. There is a significant need for the unique apparatuses, methods and systems disclosed herein.